新型两性双子表面活性剂的合成与表面活性研究

以十二烷基叔胺、环氧氯丙烷和氯乙酸为原料,利用两步法合成了双季铵盐羧甲基钠盐新型两性双子表面活性剂,采用元素分析、红外光谱对其结构进行了表征,考察了反应条件对合成反应收率的影响。第一步合成最佳条件为:n(叔胺):n(盐酸盐):n(环氧氯丙烷)为1.0:1.1:1.0,反应时间18 h;第二步合成最佳条件为:n(双季铵盐):n(氯乙酸)为1.0:1.4,反应时间3 h,反应温度40℃,NaOH质量分数为25%,产物收率达96.5%。产物CMC为0.06 mmol/L,γCMC为18.4 mN/m,优于季铵盐阳离子双子表面活性剂及传统两性表面活性剂。

STUDY ON SYNTHESIS AND SURFACE ACTIVITY OF A NOVEL AMPHOTERIC GEMINI SURFACTANT

A novel amphoteric gemini surfactant was synthesized from dodecyl dimethyl amine,epoxy chloropropane and chloroacetic acid by a two-step synthesis method.The structure of the product was characterized with elemental analysis and IR.The influences of reaction conditions on the yield were studied.The optimum conditions of step one was:molar ratios of tertiary amine and hydrochloride and epoxy chloropropane 1.0:1.1:1.0,and reaction time 18 h.The optimum conditions of step two was:molar ratio of biquaternary ammonium salt and chloroacetic acid 1.0:1.4,reaction time 3 h,reaction temperature 40℃,and 25%NaOH,with the yield of the product being 96.5%,The critical micelle concentration(CMC) of the amphoteric gemini surfactant was 0.06 mmol/L and the surface tension(γ_(CMC)) was 18.4 mN/m.The surface activity of the amphoteric gemini surfactant is superior to gemini quaternary ammonium salts cationic surfactants and conventional amphoteric surfactants.